Method of finishing the edge of a material



Aug. 9, 1932.

E. POWELL METHOD OF FINISHING THE EDGE OF A MATERIAL Filed Sept. 20 1929 Patented Aug. 9, 1932 UNITED STATES- PATENT oFFIcr.

RAYMOND E. POWELL, OF WESTFIELD, JERSEY, ASIGN OR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, 015 NEW YORK, N. Y., A CORPORATION OF NEW YORK METHOD OF FINISHING THE EDGEOF A IVLA'ILERIAL Application filed September 20, 1929. Serial No. 393,924.

This invention relates to a method of finishing the edge of a material, and more particularly to a method of finishing and sealing the edge of a braided textile cable covering. v

In telephone exchange equipment cables composed of a plurality of insulated wires covered with an exterior common textile braid are frequently used. In order that such electrical cables may be connected to the apparatus of the exchange equipment the covering or sheathing of the cable is removed for some distance from the end of the cable to render the conductors accessible for converting them into suitable formations for connecting with the terminals of the apparatus, and such removal of the cable sheath leaves a frayed, roughyor abrupt surface or edge at its end which it is desirable to render smooth '20 or finish in some way. It is also desirable In accordance with this object one embodiment of the invention consists in serving the 5 edge of a braided textile cable covering and contiguous portions of projecting insulated conductors of the cable with a kind of artificial silk such as cellulose acetate strands and treating such strands with a solvent such as acetone to partially dissolve them and produce a smooth, even, impervious seat over the cable covering edge and adjoining portions of the projecting cable conductors, thus providing a smooth and even finish for the edge of the cable covering and hemming in or enclosing the conductors which may be bent outwardly in the form of a fan at this point.

A clear understanding of the invention will be had by referring to one specific embodicable.

ment thereof as illustrated in the accompanying drawing, wherein Fig. 1 is a perspective view of a flat switchboard type of telephone cable with the end of its sheath removed and requiring the finishing of the edge as provided by this invention, and Fig. 2 is a fragmentary section of the cable shown in Fig. -1, taken transversely of the Referringnow to the drawing in which like numerals designate similar parts in the two views there is disclosed a telephone cable having the end of its sheath or covering re moved to expose the insulated conductors 5' thereof for connection with apparatus by bending them into the shape of a fan or otherwise bending them laterally of the cable. The covering or sheathing of the. cable may consist of a number of layers of paper, foil, and

textile or fabric in a variety of combinations but in this particular case the sheathing is shown to comprise a layer of paper 6, then a layer of foil 7, which may be of lead, and an outer layerofbraided textile 8, which may be of cotton threads. It-is apparent that with these three adjoining layers 6, 7, and 8 of covering abutting the insulated conductors 5, an abrupt and possibly frayed joint or edge will be formed therebetween, and it is the purpose of this invention to provide a smooth and even junction between these two surfaces, furnishing a seal therebetween and at the same time reinforcing the sheath edge to prevent fraying and abrasion thereof. Accordingly, a thin layer 9 of artificial silk consisting preferably of cellulose acetate strands or fibres is served or wrapped around the edge of the cable sheath'and adjoining portions of the insulated conductors 5 to provide a smooth junction between these two surfaces. The cellulose acetate strands are then treated orsprayed with some suitable solvent therefor such as acetone to partially dissolve the surfaces of the cellulose strands and cause them to adhere to each other and to the cable sheath edge as well as to the contiguous portion of the'conductors 5, forming a smooth, impervious seal therebetween. Thus it is believed to be apparent that the layer 9 of cellulose acetate fibres treated with 2 restore a solvent such as acetone produces a fine, silky and smooth even juncture between the edge of the cable sheath. and the emerging conductors 5, thereby preventing fraying of the sheath edge and also reintorcing it against abrasion due to the fact that the conductors 5 are bent laterally of the cable for connection to apparatus.

Uf course it will be understood that other w silky threads or strands of material than the cellulose acetate 9 be used for producing the oint, as long as they coalesce and adhere to each other when treated with a solvent to produce an impervious seal. Thus nitro-cel lulose or other silky fibres may be used in place of the cellulose acetate. Also it will'be apparent that other solvents than acetone may be used for dissolving these fibres, a mixture of ether and alcohol, tetrachloralethane,

so ethylacetate, diacetone alcohol methylethyh eketon and benzol acetate also suitably serving this purpose. With a joint made between the cable sheath and conductors as atoredescribed, it is apparent that a fine, smooth finish of the edge of the sheath is accomplished and that the sheath edge will be prevented from becoming frayed.

It will be understood that the invention is not to be limited by its specific embodiment here described and illustrated, but is to be,

limited only by the scope of the appended claim.

What is claimed is: i A method of finishing the edge of the'cov'er ing of an electrical cable of non-circular crosssection, consisting in wrapping a layer of cellulose acetate fibres around the edge of the covering and contiguous conductor portion of the cable, and applying acetone to the 4 fibres to partially dissolve them and thereby form an impervious seal between the edge of the covering and the contiguous conductor portion of the cable.

In witnesswhereof, I hereunto subscribe my name this sixth day of September A. D.,

- RAYMOND E. POWELL. 

